.hear {

    background-color: aquamarine;
    margin-left: 0px;
    width: auto;
    height: 200px;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    text-align: center;
    border: 1px solid #000; /* 只是为了方便看到边界，可根据实际情况去*/
    overflow: hidden; /* 超出部分隐藏 */
}
.hear h1{
    position: absolute;
    font-size: 100px;

}
.hear img {
    display: block;
    width: 100%;
    height: auto;
    margin-top: 10px;
    object-fit: cover; /* 保持宽高比填充整个容器，超出部分裁剪 */
}
.options {
    display: block;
    width: auto;
    height: 50px;
    margin-top: 1px;
    background-color:white;
}
.content-section {
    display: none;
}
#Borrow-classroom {
    display: block;


}
#content{
    height: auto;
    width: auto;
    /* position: absolute; */
    /* background-color: salmon; */

}
nav{
    background-color: #333;
    overflow: hidden;
}
nav a {
    float: left;
    display: block;
    color: white;
    padding: 14px 16px;
    text-decoration: none;
}
nav a:hover {
    background-color: #555;
}
nav a:active {
    background-color: #4CAF50;
}

table {
    border-collapse: collapse;
    width: 100%;
}
th, td {
    border: 1px solid #ccc;
    padding: 8px;
    text-align: center;

}

#Borrow-classroom button{
    padding: 10px 20px;
    font-size: 16px;
    background-color: #007BFF;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    box-shadow: 2px 2px 5px rgba(0, 0, 0, 0.2);
}
.collapsible-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-in-out;
}
.options select
{
    padding: 5px;
    font-size: 18px;
    color: #333;
    border: 1px solid #ccc;
    border-radius: 5px;
    box-shadow: 2px 2px 5px rgba(0, 0, 0, 0.1);
    width: 225px; /* 设置宽度为 200 像素，可以根据需要调整 */
    height:50px; /* 设置高度为 40 像素，可以根据需要调整 */
}
.options input{
    padding: 0px;
    font-size: 20px;
    color: #333;
    border: 1px solid #ccc;
    border-radius: 5px;
    box-shadow: 2px 2px 5px rgba(0, 0, 0, 0.1);
    width: 226px; /* 设置宽度为 200 像素，可以根据需要调整 */
    height:47px; /* 设置高度为 40 像素，可以根据需要调整 */
}

.options input[type="submit"] {
    padding: 10px 20px;
    font-size: 16px;
    background-color: #007BFF;
    color: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    box-shadow: 2px 2px 5px rgba(0, 0, 0, 0.2);
}